In this paper, we prove that a linear action of a reductive group on a polynomial ring with good ltrations over a eld of characteristic p > 0 yields a strongly F-regular (in particular, Cohen-Macaulay) invariant subring. The strongly F-regular property of some known examples of invariant subrings, such as the coordinate rings of Schubert varieties in Grassmannians, are recovered. A similar resu...

The equivalence between autonomicity and the absence of free variables is a well-known result for linear, shift-invariant and complete behaviors over a field. However, this no longer holds for a behavior that does not satisfy one of those properties. In this paper we consider linear, shift-invariant and complete behaviors over the ring Zpr and study under which conditions such behaviors are aut...

We consider a finite dimensional indecomposable modular representation of a cyclic p-group and we give a recursive description of an associated separating set: We show that a separating set for a representation can be obtained by adding to a separating set for any subrepresentation some explicitly defined invariant polynomials. Meanwhile, an explicit generating set for the invariant ring is kno...

We improve Kemper's algorithm for the computation of a Noetherian normalization of the invariant ring of a nite group. The new algorithm, which still works over arbitrary coeecient elds, no longer relies on algorithms for primary decomposition.

We show that any quasi-Gorenstein deformation of a 3-dimensional Buchsbaum local ring with I-invariant 1 admits maximal Cohen-Macaulay module, provided it is quotient Gorenstein ring. Such class rings includes two instances unique factorization domains constructed by Marcel-Schenzel and Imtiaz-Schenzel, respectively. Apart from this result, motivated the small conjecture in prime characteristic...

Let G be a finite group of complex n× n unitary matrices generated by reflections acting on C. Let R be the ring of invariant polynomials, and χ be a multiplicative character of G. Let Ω be the R-module of χ-invariant differential forms. We define a multiplication in Ω and show that under this multiplication Ω has an exterior algebra structure. We also show how to extend the results to vector f...

In this article we study the structure of highest weight modules for quantum groups defined over a commutative ring with particular emphasis on the structure theory for invariant bilinear forms on these modules.

We genaralize the ground ring struture to all other special BRST invariant operators in the right branch in the c = 1 Liouville theory. we also discuss correlation functions of special states on the sphere.